//import { vfApp } from '@/utils/create-app'

export function addDirective(app) {


  /**
   * 拖拽指令使用方式：v-drag="[dragDom, dragHeader]"，如 `<div v-drag="['.drag-container .el-dialog', '.drag-container .el-dialog__header']"></div>`
   */

  app.directive('drag', {
    mounted(el, binding) {
      if (!binding.value) return false;

      const dragDom = document.querySelector(binding.value[0])
      const dragHeader = document.querySelector(binding.value[1])

      dragHeader.onmouseover = () => (dragHeader.style.cursor = `move`);

      function down(e, type) {
        // 鼠标按下，计算当前元素距离可视区的距离
        const disX = type === 'pc' ? e.clientX - dragHeader.offsetLeft : e.touches[0].clientX - dragHeader.offsetLeft;
        const disY = type === 'pc' ? e.clientY - dragHeader.offsetTop : e.touches[0].clientY - dragHeader.offsetTop;

        // body当前宽度
        const screenWidth = document.body.clientWidth;
        // 可见区域高度(应为body高度，可某些环境下无法获取)
        const screenHeight = document.documentElement.clientHeight;

        // 对话框宽度
        const dragDomWidth = dragDom.offsetWidth;
        // 对话框高度
        const dragDomheight = dragDom.offsetHeight;

        const minDragDomLeft = dragDom.offsetLeft;
        const maxDragDomLeft = screenWidth - dragDom.offsetLeft - dragDomWidth;

        const minDragDomTop = dragDom.offsetTop;
        const maxDragDomTop = screenHeight - dragDom.offsetTop - dragDomheight;

        // 获取到的值带px 正则匹配替换
        let styL = getComputedStyle(dragDom).left;
        let styT = getComputedStyle(dragDom).top;

        // 注意在ie中 第一次获取到的值为组件自带50% 移动之后赋值为px
        if (styL.includes('%')) {
          styL = +document.body.clientWidth * (+styL.replace(/%/g, '') / 100);
          styT = +document.body.clientHeight * (+styT.replace(/%/g, '') / 100);
        } else {
          styL = +styL.replace(/\px/g, '');
          styT = +styT.replace(/\px/g, '');
        }

        return {
          disX,
          disY,
          minDragDomLeft,
          maxDragDomLeft,
          minDragDomTop,
          maxDragDomTop,
          styL,
          styT,
        };
      }

      function move(e, type, obj) {
        let { disX, disY, minDragDomLeft, maxDragDomLeft, minDragDomTop, maxDragDomTop, styL, styT } = obj;

        // 通过事件委托，计算移动的距离
        let left = type === 'pc' ? e.clientX - disX : e.touches[0].clientX - disX;
        let top = type === 'pc' ? e.clientY - disY : e.touches[0].clientY - disY;

        // 边界处理
        if (-left > minDragDomLeft) {
          left = -minDragDomLeft;
        } else if (left > maxDragDomLeft) {
          left = maxDragDomLeft;
        }

        if (-top > minDragDomTop) {
          top = -minDragDomTop;
        } else if (top > maxDragDomTop) {
          top = maxDragDomTop;
        }

        // 移动当前元素
        dragDom.style.cssText += `;left:${left + styL}px;top:${top + styT}px;`;
      }

      /**
       * pc端
       * onmousedown 鼠标按下触发事件
       * onmousemove 鼠标按下时持续触发事件
       * onmouseup 鼠标抬起触发事件
       */
      dragHeader.onmousedown = (e) => {
        const obj = down(e, 'pc');
        document.onmousemove = (e) => {
          move(e, 'pc', obj);
        };
        document.onmouseup = () => {
          document.onmousemove = null;
          document.onmouseup = null;
        };
      };

      /**
       * 移动端
       * ontouchstart 当按下手指时，触发ontouchstart
       * ontouchmove 当移动手指时，触发ontouchmove
       * ontouchend 当移走手指时，触发ontouchend
       */
      dragHeader.ontouchstart = (e) => {
        const obj = down(e, 'app');
        document.ontouchmove = (e) => {
          move(e, 'app', obj);
        };
        document.ontouchend = () => {
          document.ontouchmove = null;
          document.ontouchend = null;
        };
      };
    },
  })

  // v-dialogDragWidth: 弹窗宽度拖大 拖小
  app.directive('dialogDragWidth', {
    mounted(el, binding) {
      const dragDom = binding.value.$el.querySelector('.el-dialog')

      el.onmousedown = (e) => {
        // 鼠标按下，计算当前元素距离可视区的距离
        const disX = e.clientX - el.offsetLeft

        document.onmousemove = function(e) {
          e.preventDefault() // 移动时禁用默认事件

          // 通过事件委托，计算移动的距离
          const l = e.clientX - disX
          dragDom.style.width = `${l}px`
        }

        document.onmouseup = function(e) {
          document.onmousemove = null
          document.onmouseup = null
        }
      }
    }
  })

}

